Question

ina Rhombus abcd if m angleb=60 and Ac=8 find out the perimeter​

Answer 1

Answer:

Ac=diagonal

= 8cm

L B = 60

LC = 120 (Cointr. angle )

triangle ABC is equilateral

Ac=8, AB=8, BC=8

Similarly CD=8, AD=8

Perimeter=8x4=32m

Answer 2

Perimeter of Rhombus = 32unit

Step-by-step explanation:

Given,

In rhombus ABCD

∠B = 60° and AC = 8

AB = BC = CD = DA [In a rhombus all sides are equal]

In ΔABC,

AB = BC

⇒∠BAC = ∠BCA (Angle opposite to equal sides are always equal)

∠BAC + ∠BCA + ∠ABC = 180° (Angle sum propert of a triangle)

∠BAC + ∠BAC + 60° = 180°

2∠BAC = 180° - 60°

2∠BAC = 120°

∠BAC = $\frac{120}{2}$°

          = 60°

⇒ ∠BAC = ∠BCA = ∠ABC = 60°

⇒ AB = BC = AC

Since AC = 8

⇒AB = 8 = AB = BC = CD = DA

Hence Perimeter of Rhombus = AB + BC +CD +DA

                                                   = 8 + 8 +8 + 8

                                                   = 32 unit